More than half of the world's population suffers micronutrient malnutrition. The main sources of minerals (iron and zinc) for low-income rural and urban populations are staple crops such as wheat, maize, and rice, which often contain low levels or low bioavailability of these micronutrients. Biofortification, a new strategy to help fight micronutrient malnutrition, aims to develop micronutrient-enhanced crop varieties. HarvestPlus, the CGIAR's biofortification initiative, seeks to breed and disseminate crop varieties with enhanced micronutrient content that can better the nutrition of the hard-to-reach (by fortification or supplementation programs) rural and urban poor in targeted countries/regions. Wheat varieties biofortified with increased Zn levels can be developed through conveng> tional plant breeding, but a transformation approach may be necessary in the case of Fe due to its significantly higher target levels compared to Zn. In attempting to enhance micronutrient levels in wheat through conventional plant breeding, it is important to identify genetic resources with high levels of the targeted micronutrients, consider the heritability of the targeted traits, explore the availability of high throughput screening tools, and gain a better understanding of genotype by environment interactions. Biofortified wheat varieties must have trait combinations that trigger adoption, such as high yield potential, disease resistance, and consumer acceptability. When defining breeding strategies and target micronutrient levels, researchers need to consider the desired micronutrient increment, food intake, retention, and bioavailability as they relate to food processing, promoters, and inhibitors. In terms of transformation, there seem to be many opportunities to improve Fe and Zn grain concentration. However, there is a great need to better understand the genetic mechanisms underlying Fe and Zn mobilization, transport, and deposition in the grain, as well as the mechanism regulating the distribution of the two metals within the different tissues of the grain. Similarly, a better understanding of the physiological processes that control root absorption and translocation will be needed.

Conservation Agriculture Program

Text in English

INT1421

CIMMYT Staff Publications Collection